Method of making baking or like pans



Jan. 6, 1953 E. l. GHORMLEY METHOD OF MAKING BAKING OR LIKE PANS Original Filed July 6. 1948 lNvENToR bw/N Z Quo/:Muy

Patented ian. 6, 1953 METHOB F BIAKIN PA G BAKENG 0R LKE NS Edwin I. Ghormley, Dayton, Ghia, assignor to Unitedvvr Aircraft Products, Inc., Dayton, Ohio,

a-l corporation of 'Ohio Griginal application July 6, 1948, Serial No. 37,163. Divided and this application July 28,

1948, Serial No. 41,043

6 Claims.

This is a division of'myapplcationserial Number 37,163, filed July 6, 1948; for-Machine'ior and Method of Metal Working.

The'present invention relatesr to" methods of manufacture of baking andllikepans., The invention has'especial; although not limited, referenceA to' baking. pans characterized' by a, deep annular recess or cavity,A for example Ato pans used in preparing angel focdcakes;

Such pans have heretoiore'b'een made asv fabricated articles, madev up of two or;l more parts separately formed and4 connected together by a brazing or like process; This method', which involves vmultiple stepstand` handling, isV time consuming and relativelyexpensive. Moreover, the resultant product .lacks attractiveness'l of appearance and since ity presents surface cracks: and crevicesV is dicultv to clean. Attemptsv to form unitary one-piece pans by drawing or on a punch press havev been unsuccessful; because elongation of the metal Without tearing and Without an irregularl distribution of" material hasnot been possible.

Itis an object of thepresentinvention to produce a one-piece pan ofthe, class described, free of the objections above'notedby a method consistently yielding a product* conforming to the design characteristics;

Morespecically it is an object ofthe invention to. utilize rotary extrusion pressureto form la pan of the class .describedin a single operation;

Another object is to shape a flat metal blank into a baking pan characterized by'a deepannularV recess, the side,y wallsv oiwhich are of lesser thickness than the. bottom; acre-latedV object'in this connectionY beingv to promote" aY more uniform rate, cflhe'at exchange; over the complete areafofV thes pan in the. interests ofjrnore rapid, efficient baking.

Other objectsandi` details vof' the pan and method willAA appear from the following'. descriptionwhen read. in` connection with the accompanying.,drawingaowherein:

lilig. l. isy a.. fragmentary View in longitudinal section. ofa machine for' carrying out themethod of invention; v v

Fig/2. is a View, ihcpe'rspeotive ofV a baking pan produced in accordance with the present invention;,and. v

Fig. 3"is a view-n cross section, taken substantially. along the line 3*-3'of Fig; 2:

The invention is lclisclosed'in connection with a baking pan but it 'will be understood that the method forminga para o-tthe invention has a wicerapnlicancain-.sheet-m a-ifworking. sach 2 method appears to-present a. generally newfand! better means of'dening ak deep. annularrecessin a pieceof sheetY metal, as compareditoknown prior artpractice.

Referring to Figs. 21v and 3 of the, drawings, a baking pan made in accordance with theirpresentV invention is a onepiece unitary structureifformed from a single piece of. sheet metal, as will here;- inafter appear. The pan comprises a rimportion It, a bottom portion II, an outerwall; I?, and' aninnervwall I3; Therim I0 may originally lie in a plane parallel to the bottom II but during the formingprocess orA as an additionalY step thereto is turned down as* indicatedt The/Walls I2 and I3' arespaced: apart: andinterconnected by the bottom II'and define therebetween: a; relatively deep annular'recessor space i4'. Thewalls are oppositely inclined: relativeflyttoY eachA other in such wise that-.annularfspace I4 has a tapered formation extending from ,an area: oi: minimum width adjacent the bottom' l I-toanf,area= of maximum width adjacent the rim I0; The:inner wall i3 is centrally locatedwith respect to wall I2 and projects as a frustoconi'cali horn upward. through and beyond the'planeof the ;rim I0; The frustum of the horn or cone has an opening I5 cut therein and the. base of. the horn: opens through the bottom II'.

The Walls |21 and I3f aref of'-V lesser thickness than the rim Il), .the bottom I'Ii and the: frustumA of the cone or innerl walll I3; thek relatively` thin walls being reinforced' and strengthened. by: theV heavier sections ofA the. pan; The construction and arrangement is rsuch*V as to permitv a more uniform and rapid rateoffheatexchange.l That is, heat applied directly'toz'the-bottom II' and less directly to the walls IZ'and I-3'is transmitted to space'lllv at approximately the samerate so that baking may proceed relatively quickly and lat more nearly the same rate throughout the cake batter than is the case whenthe bottom and'side Wallsfare equally thick. Further, by the method of the invention it is possibley tomake the side walls If2- and I3 relatively steep-andthespace ILI deep, sov that heat may beapplied directly toa large area of the baking/space HIL The-pan'is shapedfrom aatmetal blank-according to a rotary extrusion process. by Which both side walls Ii.- and t3@ and interconnecting bottom H are formed inazsingle: operation. vA machine fori carrying out; suchn met-nodi is described andclaimedinimy parentapplication; previously referred to; i

lThe machine; there: described.A isiny part shownY herein" in Fig.: l. '.Asrmay bev seen therein,v the machine comprises a base |6 to which is secured a rst set of guideways l1, a second set of guideways I8 and a plate I9. The guideways l1 provide a track support for an anvil assembly 2| including a block 22, an integral rib 23 andy tenons 24 on the rib 23 slidably mounted in guideways |1. The guideways I8 provide a track support for a plate 25 upon which is mounted an upright blank holder 26. The holder 26 has a large central opening 21 therein and is adapted to retain in an upright position a flat metal blank 28 from which the baking pan is formed. The plate |9 provides a mount for a housing 29 in which a spindle 3| is rotatively arranged in bearings 32.

The anvil assembly 2| and the spindle housing 29 are mounted in opposed coaxial relation upon the base I6 and the blank holder 26 lies therebetween. The anvil assembly is reciprocable relatively to the guideways |1 toward and away from housing 29 While spindle 3| is rotative relatively to the housing 29 and to the anvil assembly. The blank holder 26 is resiliently urged in a right hand Vdirection by means of a push rod 33 abutting plate 25 and extending through plate |9to a resilient pressure source such as a spring or compressed air accumulator. The holder 26 moves under the control of the resilient pressure source and of the anvil assembly 2| and permits engagement and shaping of the blank 28 by the working parts through central opening 21 therein.

The anvil assembly 2| further comprises a rst die member 34 circular in shape and secured to the front face of block 22 adjacent the periphery thereof, and a second die member 35 frustoconical in shape and secured to the front face of block 22 centrally thereof. The die 34 has a sloping inner wall corresponding in pitch and length to the outer wall l2 of the baking pan and provides the anvil upon which this wall of the pan is formed. The central die member 35 is externally dimensioned in accordance with the shape of the inner Wall |3 of the pan and is the anvil upon which this Wall is formed. rIogether the block 22, anvil 34 and anvil 35 define the die mold. The anvil or die member 35 has a locating projection 36 on the base thereof received in a central opening 31 in the block 32. Also received in the opening 31 on the opposite or rear face of the block 32 is a reduced diameter portion of a nut 38. The nut 38 is internally threaded for connection with a shaft 39 and is held to the block 22 by bolts 4|. The shaft 39 extends rearwardly in a manner not here shown into cooperative relation with a hydraulic cylinder or like device whereby power initiated reciprocable motion may be imparted to the anvil assembly.

The anvil assembly additionally comprises an ejector ring 42 reciprocable within the space between anvil elements 34 and 35' and adapted to seat in the bottom of such space upon the front face of block 22. The ring 42 has a set of rods 43 anchored thereto and extending through the block 22 toward abutting engagementv with a fixed stop 44 and has another set of rods 45 anchored thereto and extending rear Wardly through block 22 toward cooperative engagement with a fixed stop 46, which stop may be integral with or the same part as stop 44. The rods 45 extend through and beyond stop 46 and have nuts 41 thereon arranged to limit against stop 46 in forward movement ofthe' ejector ring. The construction and arrangement is such that when the anvil assembly moved in a forward, or left hand, direction as viewed in the drawing, ejector ring 42 is carried therewith until the nuts 41 on rods 45 engage stop 46. Thereafter the anvil assembly moves relatively to the ejector ring which is caused to assume a seated position adjacent block 42. When the anvil assembly moves on its return stroke, and in a right hand direction as viewed in the drawing, the ejector ring 42 moves in accompaniment therewith until the rods 43 engage stop 44 Whereupon the continued motion of the assembly is accomplished relatively to the ejector ring. The controlled motion of the ejector ring is utilized, as the name implies, to aid in removing a iinished pan from the die mold.

The spindle 3| projects at the inner or right hand end thereof through and beyond bearing 32. The outer or left hand end of the spindle is arranged to be connected to an electric motor or like device'. whereby the spindle may berotatively driven. Secured to the inner end of the spindle is an enlarged head 48. The head 48 Vhas a counterbore 49 communicating with a longitudinal bore 5| in spindle 3| and further is intersected radially by three sets of slots 52 and 53. The slots of each set 52 and 53 are spaced equidistant from one another about the front face of the head 48, and are arranged in alternating relation with respect to the slots of the other set. A pivot pin 54 and 55 is passed transversely through each slot 52 and 53 and pivotally mounted upon each pin 54 and 55 is a respective arm 56 and 51. The arms 56 and the arms 51 are slotted at their outer extremities and rotatably carry, in such slots, forming and pressing rolls indicated respectively at 58 and 59.

The presser arms 56 and 51 thus are arranged to revolve with the head 48 about the axis of spindle 3| and further are movable in rocking or rotative directions about the respective pivots 54 and 55. Rocking motion of the arms is initiated and controlled by a cam member 66 and reciprocable within counter bore 49. The cam member 60 has a plurality of longitudinal peripheral grooves 6| and 62 arranged in alternating spaced relation corresponding to the alternating positions of the arms 56 and 51. Rollers 63 on the arms 56 are received in grooves 6| while rollers 64 on the arms 51 are received in grooves 62. The grooves 6I and 62 taper toward the front end of cam element 66 to produce an oscillating motion of the arms 56 and 51 in response to reciprocation of the camelement. In the case of arms 56, the pivot pins 54 are placed intermediate the ends of the arms so that a forward or right hand direction of motion of cam element 60 produces a swinging motion of the outer ends of the arms toward the axis of spindle 3|. In the case of arms 51, the pivot pins associated therewith are placed at the inner ends of the arms so that a forward or right hand direction of motion of cam element produces a swinging motion of the outer ends of the arms away from the axis of spindle 3|. A backward or left hand direction of motion of the cam element 66 results in correspondingly opposite direction of movement of the arms 56 and 51. The cam element 60 is urged in a right hand or outer direction by acoil spring 64 disposed in bore 5| and mounted upon a guide rod 65 anchored to the rear of cam element 60. Upon the front rend of cam element 60 is a friction plate 66 rotatable independently of element '69 by reason of ,an intermediate bearing 61. Radi- .Theiblanlifbolrler 2.6 llas a limitedmetionin the dreet ir1 in. which it is urged by .push rod .3.3, Weigh-.li ltisrleiirred. bythe externer `ex- .perlsiQn .Dermittedthe resilient pressure source During. the 'forwardmfztgn Qf. the anvil. assemlfyr the .anvil member '3.4 may engage. .holder .tt

andl meveitrearwardlv .Or a left band .direetien' .against .tbeactien of the resilient pressure Ierse' @urine the. retreetine stroke. of the l anvil assembly the ihQlrle. .2.6 fellowsthe..ani/.11534 .until'its limit 0f: mollen- Il that .direetionisreaehed Wliereunerlfthe anvili'tll .moves away .from the "h Qlder.- P Qsitiflnspf the Parts-attained .when the anvilassemblv is at. theerlel of its retraetine stroke 'is .indicated ,1., although ythis view .is intended t0 show the. .assembly .moving .toward Athe work.

With Ithe machine at rest, the parts assume approximately the positions shown in Fig. 1 wherein axial retracting lmotion of the anvil assembly has separated the anvil 34 from the blank :holder 2.6 which -stands at the limit o f its Aout- Aand inline with the edge of the yfrustum of .anvil ,35. The arms 51 have been spread apart by cam A{if} in a divergent direction, to move the rolls 56 away from the axis of head 4B and in line with the inner edge of the land defining the start of the internal .slope of anvil 34.

Preparatory to starting the working stroke of themachine, the sheet metal blank 2B isV placed against vthe holder I4 on that side facing the anvil assembly. There is then s'et in motion the hydraulic cylinder operable upon shaft 39. The shaft Sais-moved thereby forwardly or ina left hand direction as Viewed Vin Fig. 1, and, in the course of such movement, the frustum of anvil contacts the metal blank 28. Continued motion of the anvil assembly thus serves to move the blank 28 and holder 26 toward the head 48 against the relatively low resilient pressure applied in opposition through rod 33. At or about the same time forward motion of the anvil assembly is initiated, rotary motion of the spindle 3| is begun. The arms 5'6 and 51 partake of such rotary motion and revolve in the planes indicated in Fig. 1 about the axis of the spindle. As the anvil assembly approaches the arms 56 and 51, the rolls 58 and 59 of the presser arms engage the metal blank 28, the rst said set engaging the blank adjacent the center thereof and the second said set engaging the blank adjacent the periphery thereof. Under the influence of continuously applied axial pressure'by the anvils, the blank 28 is forced by the presser arms to a seat upon the anvils. In response to further rotation of the presser arms, the metal of the blank is pressed against the sloping walls of the respective anvils 34 and 35 and caused to assume the formation defined by the anvils. At or about the same time that the rolls 58 and 59 on the presser arms engage the metal blank 28, the anvil 35 through the blank engages the friction plate 66 on cam element 60. Further axial movement of the anvil assembly accordingly results in a. retracting or left hand direction of movement, as viewed in Fig. l,

6 ef .the cam element to.. The .rollers .63' .and 6.4 .are enabled :thereby to fonow `the descending slope of the.. grooves .6l and ,6 2 in the. .Cam with the result-that the rolling. and.v pressing ypressure applied by the ro11si58. on `the arms. Y561s de- .veloped .gradually outward .from the. axis yofthe spindle whereas the similar pressure applied .by rolls 59 on `ar1ns'5! ldevelops gradually inward. The motion of the presser, arms .under ,theaction of cam 6 0 is ,keyedto theslope of the anvilsfSll and 3.5.irrs11eh wise that therous stand 5 9 follow v the contour .O f the anvils ,and press .the metal of the `blank closely against. the sloping .walls thereof. The, forward, motion of .theanvilassemblyis. limited by suitablemeansoperable to. interrupt the stroke .thereof when the rolls. 5 8 and 56 Von thepresser Varms have reached thebottom of the annular recess betweenyanvils 3 4 and .3.5.

.lli .will he. observed that .the action of the 91165561', arms, is suchI as tobe without. ,effect4 on that area .of the-metal blank which .is notenga'eed bythe arms.. ,Thisarea which is .annular inshapefseparatesthe shaped walls of thablank and defines the 1 bottom ,I I of .thebaking `pan-pro- ,Cll'ced bythe operation. Tha-t area oi. the metal blank .acted upon4 yby arms 56 conforms. `to the shapeof the. frustofconicalganvil-,35 and Ais caused thereby toassume a corresponding shape .and this area accordmgly becomes the centralcone |,3 of vthe pan. The area of themetal-blank acted upon by arms5'i is made to conform to .the slope. of the internal `wall ofV anvil` 3.4:andthis area` of4 the .blank accordingly becomes vthe side .Wall :lf2 .of the pan. The area ,o f. the metal blank resting, uponthe end of anvil .314 is clamped b etweensuchfl'and .and the. holder i4 and .becomes the rim or the pan vand may lie parallel tothe .bottom` Itwill be lfurther noted and understood' thatthe action .of the rolls 58 and., 5,9 againstthecounterpressure applied by the anvils. 3l! and 35 -is-.suchas todraw or extrude; the, metal acted upon. withou-ti adding -to or taking away from `themeta-l-of the'rim-and of the. bottom. In consequence, and' asvv seen in Fig. 3, the outer wall of the pan and the central cone thereof are relatively thinner than the rim and bottom portions of the pan.

When the pan has been so formed in the die mold, a, retracting stroke of the anvil assembly is initiated and rotary motion of the spindle 3| may be discontinued. The anvils 34 and 35 accordingly move away from the presser arms 56 and 51 and return to the position shown in Fig. 1. The blank holder 26 follows the return motion of the anvils until the limit of its motion is reached whereupon the anvils continue on independently of the holder. The distance of retraction of the anvil assembly and the limit placed upon the following motion of the holder 26 is such as to provide at the end of the return stroke of the anvils, a space of sufficient width between the anvils and the holder 26 as to permit withdrawal of the finished pan from the machine.

What is claimed is:

1. The method of forming a baking pan from a flat metal blank, said pan having spaced apart inner and outer walls defining an annular recess therein, including the step of applying separate spaced rotary extrusion pressures respectively to denne said inner and outer walls, such pressures being applied to one side of the blank beginning at the top of the recess and ending at the bottom thereof.

2. The method of forming a baking pan from a nat Imetal blank, said pan having spaced apart oppositely inclined inner land outer rwalls deningv an annular recess therein, comprising the steps of applying separate spaced rotary extrusion pressures respectively to define said inner and outer walls, such pressures being applied to one side of the blank, and gradually developing such pressures respectively inward and outward of the axis of the blank. Y

3. The method of forming ina fiat metal blank a relatively dee-p annular recess having oppositely sloping side walls, comprising the steps of applying separate spaced concentric rotary extrusion pressures respectively to Adeiine said inner and outer walls, to one side of said blank, and gradually developing such pressures respectively inward and outward of the axis of the blank.

4. A method of making a one-piece sheet metal baking pan characterized by a frustoconical central wall and an oppositely inclined outer wall, including the steps of forming a flat metal blank, simultaneously applying separate rolling and pressing pressures to said blank on one side thereof, one of said pressures being applied adjacent to the center of the blank and developing gradually outward thereof and the other of said pressures being applied outward of the center of the blank and developing gradually inward thereof, and applying a counterpressure to the opposite side' Of the blank. p

5. A method of making a one-piece sheet metal baking pan characterized by a frus-toconical central wall and an oppositely inclined outer wall including the steps of forming a at metal blank, applying a rolling and pressing pressure to one side of said blank adjacent the center thereof and gradually developing such pressure outward, simultaneously applying a similar pressure to the same side of said blank outward of the center and gradually developing such pressure inward, and effecting a, relative axial motion between said metal blank and the pressure applying devices during the application of such pressures.

6. A method of making a metal baking pan 8 Y characterized by a central frustoconicalv wall and an oppositely inclined outer wall, including the steps of forming a flat metal blank, applying an axial rolling and pressing pressure to one side of the metal blank adjacent the center thereof and gradually developing such pressure outward, simultaneously applying to the same side of said blank a similar pressure outward of the center of the blank and gradually developing such pressure inward, applying a counterpressure to the opposite side of the blank, the pressures being applied in a manner to extrude the metal acted upon, and limiting the duration of the application of such pressures to leave an annular area in the blank between and interconnecting the areas subjected to the rolling and .pressing pressures, said annular area dening the bottom ofthe pan and having a thickness greater than the thickness of said other areas which dene the walls of the pan.

EDWIN I. GHORMLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 19,790 Lindgren Dec. 17, 193.5 635,320 Hendricks Oct. 24, 1899 1,262,780 Griilin Apr. 16, 1918 1,732,554 Detwiler Oct. 22, 1929 1,903,310 Launderville Apr. 4, 1933 1,922,087 Hiester Aug. 15, 1933 1,953,934 Hiester Apr. 10, 1934 FOREIGN PATENTS Number Country Date 116,777 Switzerland Nov. 1, 1926 117,965 Switzerland Dec. 1, 1926 515,445 Germany Dec. 28, 1926 663,139 France Mar. 30, 1929 26,756 Australia July 8, 1930 33,330 Netherlands July 21, 1930 

